1. Field of the Invention
The present invention relates generally to door lock assemblies for keeping a door in a fixed position, such as door locks for keeping refrigerator display case doors closed.
2. Related Art
Commercial refrigerators and refrigerator display cases are employed in markets, food-vending operations, liquor stores and the like for the simultaneous preservation of freshness and attractive display of foods to the customer. Typically, commercial display cases have frames defining an opening for the case which is accessed through large, swinging doors having large areas of multiple-layered glazing to permit the customer to see, select and access the refrigerated product easily, while preventing heat transfer into the refrigerated space.
In some cities, grocery stores are permitted to stay open twenty-four hours per day; however, the sale of some items, such as beer and wine, have their hours of sale restricted. Thus, it would be desirable to lock the refrigerated display cases containing alcoholic beverages during the prohibited hours of sale. A lock for this purpose is described in the patent to Miller, U.S. Pat. No. 4,012,065, showing a channel-shaped body having a T-shaped slot capable of engaging a pin fastened to the display case. However, the Miller device does not prevent access by potential customers who know the construction of the device, especially since parts of the device may be visible through the glass panes of the door.
There is a need, therefore, for a lock assembly having a secure and covered lock structure which is quick and easy to use and provides a reliable lock for a door. There is also a need for a lock assembly having a removable lock which can be easily retrofit onto existing door structures, and one which is locked with an appropriate key. There is also a need for a lock assembly which includes a lock transition indication so the user can tell when the lock has made the transition between a locked and an unlocked condition. These and other needs are met by the present invention.